Yes / The content and concentration of beta-carotene, tocopherol and free fatty acid is one of the important parameters that affect the quality of edible oil. In simulation based studies for refined palm oil process, three variables are usually used as input parameters which are feed flow rate (F), column temperature (T) and pressure (P). These parameters influence the output concentration of beta-carotene, tocopherol and free fatty acid. In this work, we develop 2 different ANN models; the first ANN model based on 3 inputs (F, T, P) and the second model based on 2 inputs (T and P). Artificial neural network (ANN) models are set up to describe the simulation. Feed forward back propagation neural networks are designed using different architecture in MATLAB toolbox. The effects of numbers for neurons and layers are examined. The correlation coefficient for this study is greater than 0.99; it is in good agreement during training and testing the models. Moreover, it is found that ANN can model the process accurately, and is able to predict the model outputs very close to those predicted by ASPEN HYSYS simulator for refined palm oil process. Optimization of the refined palm oil process is performed using ANN based model to maximize the concentration of beta-carotene and tocopherol at residue and free fatty acid at distillate.

The Sungai Terah Palm Oil Mill was tasked with creating a spray drying process for drying of palm oil mill effluent based on a study conducted byThe Malaysian Palm Oil Board. The process does not work and the goal of this report was to identify the problem and recommend possible changes.This has been done through conducting a trial run, a literature study and performing thermodynamic and kinetic calculations. The results show that to reach the goal of drying 14 litres of effluent per minute the process needs a minimum of 633 kW through an increased throughput of heated air to 4.7m3/s. Additionally, the height of the drying chamber is estimated to need an increase to 8 metres. Other suggestions are also presented. / Palmoljefabriken Sungai Terah Palm Oil Mill fick i uppdrag att skapa en process som använder en sprejtork för att torka utsläppet från palmoljeproduktionen, baserat på en studie från The Malaysian Palm Oil Board. Processen fungerar inte och målet med denna rapport var att identifiera problemet och rekommendera möjliga lösningar. Detta har gjorts genom att genomföra ett fabriksexperiment, en litteraturstudie och termodynamiska och kinetiska beräkningar. Resultaten visar att processen kräver minst 633 kW genom ett luftflöde på 4.7 m3/s för att uppnå målet av att torka 14 liter utsläppper minut. Dessutom har höjden på sprejtorkens kammare uppskattats behöva öka till 8 meter. Andra förslag ges också.

[Truncated abstract] This thesis reviews the role that contract farming plays in the development process through an examination of the oil palm industry in Ghana and in the Philippines. It contributes to ongoing debates concerning agricultural liberalisation in developing economies. The general view is that while the private sector can provide access to capital, technology and markets, the transition to a market-led system will increase the financial vulnerability of farmers, particularly smallholder farmers, through unequal power relationships. Of particular concern is the capacity of the private sector to alleviate poverty and promote social equity amongst small rural landholders. At the heart of much of the debate is the issue of contract farming, which has increased rapidly in line with structural adjustment in the agricultural sector. One of the central difficulties in drawing any conclusion on whether contract farming should be encouraged or discouraged, is the lack of comparability between the large number of types of schemes, crops being contracted, the `actors' involved and the socio-economic, political and institutional environments in which contract farming schemes are nurtured. This study has focused on the role that contract farming plays in the pursuit of development through an analysis of the key socio-economic issues involved with the adaptation of contract farming in the oil palm industries in the Philippines and in Ghana. This analysis allowed for the identification of conditions under which the impacts of contract farming schemes can either be augmented or mitigated. The research found that cultivating oil palm has the propensity to reward outgrowers with increasing income and a better access to knowledge, information and technology, capital and credit, agricultural inputs, markets and other services. ... The two outgrower programs are presently successful and do not show signs of the major problems identified by researchers in other areas. However, both governments need to ensure that a comprehensive policy and regulatory framework for private sector agricultural development is put in place. A strong private sector could provide the vehicle for agricultural development and the reduction of poverty in the countryside, however, both governments and the various private sector companies engaged in oil palm production need to work in partnership with each other and the outgrower community towards the goal of a diversified and expanded agricultural production base.

Master of Agribusiness / Department of Agricultural Economics / Vincent R. Amanor-Boadu / Biofuels such as ethanol and biodiesel are looked upon as the future source of alternative energy. These biofuels will supplement the needs of the ever increasing demand for fuel. Bio-energy feedstock is in high demand and current bio-crude oil prices such as soybeans and palm oil are higher than fossil fuel crude oil prices. Unless the price of fossil fuel crude oil increases beyond that, it would not be economically viable to produce biofuels from these feedstock. Jatropha curcas has been touted as the future of biodiesel. The seeds from the Jatropha curcas are crushed and processed using transesterification. The product of the chemical reaction results in bio-oil and glycerin. The objective of this paper is to study the economics of Jatropha curcas as an alternative bio-energy feedstock. Comparisons are done on Jatropha curcas oil, soybean oil, and palm oil. The Jatropha curcas industry is at its infancy, and crude Jatropha curcas oil is either not available in the open market or extremely difficult to find in any significant amount. However, soybean oil and crude palm oil are traded commodities and their prices are dependent on their demand and supply pressures. Given these conditions, the approach adopted here involved the establishment of a vertically integrated company that grows and harvests the Jatropha curcas feedstock and crushes the seeds to obtain the crude oil, and finally processes it to obtain biodiesel and glycerin. The financial analysis provided results that indicate that the Jatropha curcas has the potential to be a successful feedstock. The conclusion after conducting net present value comparisons shows that the price per kilogram of the Jatropha curcas seed would be the determining factor in the success of this bio-fuel feedstock. As more work goes into the genetic selection of Jatropha curcas for high yield varieties, the feedstock’s potential increases and its potential as a solution to the search for the competitive sources of biodiesel becomes more real.

Thesis (MSc)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: Introduction Cardiovascular disease is one of the leading causes of death in the world. Formation of harmful reactive oxygen species (ROS) is associated with several pathological conditions, and contributes to ischaemia/reperfusion injury. Antioxidants can be added to the diet in an attempt to decrease the prevalence of cardiovascular disease by decreasing the harmful effects of ischaemia/reperfusion injury. Red Palm Oil (RPO) consists of saturated, monounsaturated and polyunsaturated fatty acids and is rich in antioxidants such as -carotene, tocopherols and tocotrienols. It has previously been shown that RPO-supplementation improved reperfusion mechanical function. In these studies it was found that RPO might exert its beneficial effects during reperfusion through increased PKB/Akt pathway activity, which may lead to inhibition of apoptosis and improved mechanical function. Aims The aims of this study were: 1) to determine whether RPO-supplementation protected against ischaemia/reperfusion injury in the isolated perfused rat heart, 2) to confirm RPO-supplementation’s effect on the PKB/Akt pathway activity and, 3) to elucidate the regulators in the PKB/Akt pathway that RPOsupplementation influenced. Methods Male Wistar rats were divided into 4 groups, 2 control groups and 2 experimental groups. The 2 control groups were fed a standard rat chow (SRC) for 4 weeks. The two experimental groups received SRC and RPOsupplementation for 4 weeks. Hearts were excised and transferred to a Langendorff perfusion apparatus and perfused with Krebs-Henseleit buffer. Mechanical functional recovery was measured after 25 min of total global noflow ischaemia. The following parameters were also measured during various time points in the protocol: left ventricular develop pressure, heart rate, coronary flow, rate pressure product. Hearts were also freeze-clamped for biochemical analysis at 10 min during reperfusion. The biochemical analysis was aimed at determining PKB/Akt involvement. In a second protocol, hearts were subjected to the same perfusion protocol, but wortmannin was also added to the perfusion fluid, in order to inhibit PI3- kinase. Results Hearts from the RPO-supplemented rats showed an improved RPP recovery (92.26 ± 5.89 % vs 63.86 ± 7.74 %) after 10 min of reperfusion. This finding corroborated the findings of previous studies. Hearts of the RPOsupplemented rats perfused with wortmannin, showed increased RPP recoveries at several time points. Biochemical results showed that wortmannin did indeed inhibit PI3-K phosphorylation in the RPO-supplemented group, as was expected. The RPO-supplemented group that was perfused with wortmannin had an increased PKB/Akt (Ser473) phosphoyrylation, when compared to the wortmannin control group. It was also found that the combination of RPO and wortmannin had prosurvival effects. Discussion This study showed that RPO-supplementation offered protection against ischaemia/reperfusion injury in the Langendorff-perfusion apparatus at 10 min into reperfusion. Thereafter the significance of the protection was lost. This protection has been confirmed in several previous studies and several mechanisms have been proposed for this protection. Since no conclusive evidence exists on the precise mechanism of protection, our investigation focused on the regulators of the pro-survival PKB/Akt pathway. An improved functional recovery was also seen in the RPO-supplemented group that was perfused with wortmannin. This was an unexpected finding, because Wortmannin is a known PI3-kinase inhibitor (as was confirmed by our biochemical data). PI3-kinase phosphorylation leads to PKB/Akt phosphorylation and therefore, activation of a pro-survival pathway. It would be expected that wortmannin would inhibit PKB/Akt and thus decrease the survival of the cells. The RPO-supplementation thus reversed wortmannin’s detrimental effect to such an extent that the functional recovery was far better than RPO-supplementation alone. In the RPO + wortmannin group, PKB/Akt (Ser473) phosphorylation was increased, contrary to previous findings. This is an indication that RPO may have the ability to override wortmannin’s inhibitory effect on PI3-kinase, or that PKB/Akt (Ser473) may be phosphorylated independently of PI3-kinase. / AFRIKAANSE OPSOMMING: Inleiding Kardiovaskulêre siektes is een van die hoof oorsake van sterftes in die wêreld. Die vorming van skadelike reaktiewe suurstof spesies word geassosieer met verskeie patologiese kondisies en dra ook by tot isgemie/reperfusie skade. ‘n Moontlike manier om die voorkoms van isgemie/herperfusie skade asook kardiovaskulêre siektes te voorkom, is om antioksidante by die dieet te voeg. Rooi Palm Olie (RPO) bevat versadigde, mono-onversadigde en polionversadigde vetsure. RPO bevat ook ‘n oorvloed van antioksidante soos β- karoteen en tokoferole en tokotriënole. Dit is bewys in vorige studies dat RPO-aanvulling verbeter funksionele herstel. Hierdie voordelige effekte mag dalk wees agv verhoogde PKB/Akt pad aktiwiteit. Die PKB/Akt pad word geassosieer met die inhibisie van apoptose en verhoogde meganiese funksie. Doelwitte Die doelwitte van hierdie studie was om te bepaal of 1) RPO-aanvulling beskermende effekte teen isgemie/herperfusie skade in die geisoleerde rotharte het, 2) Bevestig of RPO-aanvulling wel die PKB/Akt pad beïnvloed 3). om die effekte wat RPO-aanvulling het op die reguleerders van die PKB/Akt pad te onthul. Metodes Manlike Wistar rotte is in 4 groepe verdeel. 2 Groepe kontrole rotte is ‘n standaard rotkosmengsel gevoer vir 4 weke. Die 2 eksperimentele groepe het ook ‘n standaard rotkosmengsel gekry plus ‘n RPO-aanvulling vir 4 weke. Harte is uitgesny en op ‘n Langendorff perfusie sisteem gemonteer en met Krebs-Henseleit buffer geperfuseer. Meganiese funksie herstel is gemeet na 25 min totale globale geen-vloei isgemie. Linker ventrikulêre ontwikkelde druk, harttempo, koronêre vloei en tempo druk produk is gemeet by verskillende tydpunte. Sommige harte is na 10 min herperfusie vir biochemiese analiese gevriesklamp. Die biochemiese analisiese was beoog om die PKB/Akt pad betrokkenheid te bepaal. ‘n Tweede stel harte is aan dieselfde perfusie protokol blootgestel, maar wortmannin (PI3-kinase inhibitor) is ook bygevoeg by die perfusie vloeistof. Resultate Die groep wat met RPO aangevul is, het na 10 min herperfusie, ‘n verbeterde tempo druk produk herstel getoon (92.26 ± 5.89 % vs 63.86 ± 7.74. Hierdie bevinding is ook met ander studies bevestig. ‘n Interessante bevinding was dat die groep wat met RPO aangevul is en met wortmannin geperfuseer is, ‘n verbeterde meganiese funksionele herstel getoon het. Biochemiese resultate het getoon dat wortmannin wel PI3-K fosforilering geinhibeer het. Die harte van die rotte in die groep wat aangevul is met RPO en daarna met wortmannin geperfuseer is, het ‘n toename in PKB/Akt (Ser473) fosforilering getoon, relatief tot die wortmannin geperfuseerde harte van die rotte in die kontrole groep. Hierdie groep (RPO-aanvulling en wortmannin perfusie) het beskermende effekte getoon. Bespreking Hierdie studie het getoon dat RPO-aanvulling beskerming gebied het teen isgemie/herperfusie skade in die Langendorff geperfuseerde rothart na 10 min herperfusie. Daarna is die beduidenheid van die beskerming verloor. Hierdie bevindings ondersteun die resultate van vorige studies. Verskeie moontlike meganismes is voorgestel vir die beskerming, maar die presiese meganisme is nog nie duidelik nie. In hierdie studie is daar gekyk na die reguleerders van die PKB/Akt pad. Geen vorige studies het al gefokus op RPO-aanvulling en sy effek op die reguleerders van die PKB/Akt pad nie. ‘n Onverwagte bevinding is dat harte van die rotte in die RPO + wortmannin groep ‘n verbeterde funksionele herstel getoon het. Wortmannin is ‘n PI3- kinase inhibitor. PI3-K fosforilering lei tot PKB/Akt fosforilering, wat tot sel beskerming lei. Dus, aangesien wortmannin PI3-K inhibeer, sou dit verwag word dat wortmannin sel beskerming sal verminder. Die RPO het egter die wortmannin se nadelige effekte tot so ‘n mate oorskrei dat die funksionele herstel baie beter was as die RPO-aanvulling alleen. Die verhoogde PKB/Akt (Ser473) fosforilering, wat gesien is in die RPO + wortmannin groep kan toegeskryf word aan RPO se vermoë om wortmannin se nadelige effekte te oorskrei. ‘n Moontlike verduideliking vir hierdie bevinding mag wees dat rooi palm olie PKB/Akt (Ser473) op ‘n PI3-K onafhanklike manier fosforileer.

This study looks at the economic, political and social history of women in the Yoruba area of south-western Nigeria in the 19th century using contemporary sources which have remained previously largely untapped for historical studies of women. The century encompassed many key historical developments which affected women; in particular, the decline of the Atlantic slave trade and the growth of an export trade in locally produced palm oil and kernels. Whereas the slave trade had been dominated by men, the processing, transport and trade of palm produce was dominated by women. The extent, nature and effects of women's role in this and other industries such as pottery manufacture, dyeing and food vending, which also expanded and developed during this period, are examined. As demand for palm produce and other goods increased, the labour of both free-born and slave women became more valuable since it was vital for industry at all stages. The study looks at changing labour demands and sources and alterations in the established pattern of the sexual and generational division of labour. Important changes in gender relations are evident and the study illuminates how tensions between men and women and between women themselves were manifest and how both men and women expressed and dealt with these problems. Economic changes were accompanied by largely internal political developments which favoured a few wealthy women. overall, many men perceived and/or experienced that increasing female autonomy posed a threat to the established patriarchal order. The evidence represented in the thesis clearly shows how men attempted to subordinate women in general, tap into their income and limit their political involvement, mainly through the development of exploitative and restrictive aspects of male-dominated politico-religious cults, which were directed specifically at women.

During the last decades, climate change studies have been focusing more intensely on its anthopocenic essence, as the consequence of production and consumption patterns that require the intensive exploitation of the environment. In line with this school of thought, and new generations of studies on environmental crime, this work aims to present the environmentally and climate-related issues arising from land degradation in the Peruvian Amazon; focusing on those casual mechanisms developed from the collusion between Peruvian-economic policies and new private actors such as transnational corporations (TNCs). Relying on the assumption that: the processes moving the issue of climate change overcome the global space, and can be observed from regional, national or local point of view; this work's purpose is to analyze how a single country as Peru, currently considered of low ecological footprint, could, by means of the definition of national laws (environmentally and economic-related) burden climate change. The analysis focuses on a single case-study identified with the territory within the Northern Ucayali and Southern Loreto regions in Peru, and builds on the theory of state-corporate crime developed in the 1990s by Ronald C. Kramer and Raymond J. Michalowski to define the role of state-corporate relationships in the production of social harms. To show how this relationship is today shaping the globally spread issue of climate change, the analysis of the palm oil industry in Ucayali is presented as main example of a broader phenomenon of transgression and partnership between private and public spheres in Peru. In this optic, the purpose is to give further contributions to the studies of climate change as state-corporate crime, focusing on the analysis of those territory, as the Amazon, whose preservation has been identified as mayor tool against global warming and which is instead harmed by the relation between private and governments interests.

Objetivou-se avaliar a inclusão de fontes de gordura na forma de sais de cálcio na dieta sobre o desempenho e metabolismo de vacas em início e meio da lactação mantidas em pastagens tropicais. No Capítulo 3, foi realizada uma meta-análise para avaliar os efeitos da suplementação de gordura para vacas mantidas em pastagens sobre a produção e a composição do leite. A produção de leite aumentou com a suplementação de gordura, e a suplementação com fontes insaturadas deprimiu o teor de gordura do leite. No capítulo 4, objetivou-se comparar o uso do dióxido de titânio (TiO2) como marcador externo em substituição ao óxido crômico (Cr2O3) para estimar a excreção fecal e calcular o consumo de forragem e a digestibilidade. A excreção fecal tendeu ser maior para os valores estimados pelo Cr2O3. O Cr2O3 superestimou a excreção fecal comparado com a coleta total de fezes. O consumo de forragem e o consumo de MS total foram superestimados pelo Cr2O3, enquanto não foram observadas diferenças entre os valores observados de consumo e estimados pelo TiO2. A digestibilidade aparente da MS foi subestimada tanto pelo Cr2O3 quanto pelo TiO2. No capítulo 5 objetivou-se avaliar os efeitos da suplementação de vacas em início da lactação mantidas em pastagem tropical com diferentes fontes de gordura sobre o desempenho, composição do leite e variáveis produtivas ao longo da lactação. A suplementação de sais de cálcio de óleo de soja (SCOS) aumentou a produção de leite quando comparado com o grupo controle, porém foi inferior a produção dos animais suplementados com sais de cálcio de óleo de palma (SCOP). Apesar do aumento em produção de leite com SCOS, nesse tratamento o teor de gordura do leite reduziu significativamente quando comparado com o grupo controle e ao SCOP. Durante o período residual a produção do grupo que recebeu SCOP continuou maior e refletiu na produção ao longo de toda a lactação (7328 kg lactação-1) comparado ao SCOS (6575 kg lactação-1) e ao controle (6094 kg lactação-1). No capítulo 6, objetivou-se avaliar a suplementação de duas fontes e duas doses de sais de cálcio de ácidos graxos sobre o desempenho, composição do leite, parâmetros ruminais e metabólicos e balanço energético de vacas no meio da lactação mantidas em pastagem tropical. A produção de leite foi afetada pela adição de gordura, sendo influenciada pela fonte e pela dose de gordura. O teor de gordura do leite foi influenciado pela fonte de gordura suplementada. O pH ruminal não foi afetado pelos tratamentos experimentais. A suplementação com SCOS prejudicou a degradação da fibra, reduziu a produção de AGV\'s, reduziu a síntese microbiana e a produção de gordura do leite quando comparado com a fonte de SCOP. Portanto, as estimativas de consumo e digestibilidade foram melhores preditas com o uso do dióxido de titânio como marcador. Além disso, a suplementação com sais de cálcio de óleo de palma aumentou a produção de leite na lactação, não reduziu o consumo e nem a degradação da fibra. / The objective of this study was to evaluate inclusion of different sources of fat as calcium salts in the diet on performance and metabolism of early lactation cows grazing tropical pastures. In Chapter 3, a meta-analysis was performed to evaluate the effects of fat supplementation to grazing dairy cows on milk yield and milk composition. Milk yield increased with fat supplementation, and supplementation with unsaturated sources depressed milk fat content. In Chapter 4, the objective was to compare the use of titanium dioxide (TiO2) as an external marker to replace chromium oxide (Cr2O3) to estimate fecal excretion and calculate forage intake and digestibility. Fecal excretion tended to be greater for values estimated by Cr2O3. The Cr2O3 overestimated and TiO2 tended to overestimate fecal excretion compared to total fecal collection. Forage intake and total DM intake were overestimated by Cr2O3, while no differences were observed between the observed values of consumption and estimated by TiO2. The apparent DM digestibility was underestimated by both Cr2O3 and TiO2. In the chapter 5, it was evaluated the effects of fed different sources of fat to early lactation cows (from 15 to 105 DIM) grazing a tropical pasture on production variables throughout lactation (until 280 DIM). Calcium salts of soybean oil (CSSO) increased milk yield compared to control, but was lower than the production of animals supplemented with calcium salts of palm oil (CSPO). Despite the increase in milk yield with CSSO, this treatment decreased milk fat content and yield when compared with control and CSPO. During the residual period (from 106 to 280 DIM) the group that received CSPO had greater milk yield and reflected in the greater milk yield throughout lactation (7328 kg lactation-1) compared to CSSO (6575 kg lactation-1) and the control (6094 kg lactation-1). In chapter 6, the objective was to evaluate the supplementation with two sources (CSSO vs. CSPO) and two doses (400g vs 700g/day) of calcium salts of fatty to mid lactating dairy cows grazing a tropical pasture on performance, milk composition, ruminal and metabolic parameters and energy balance. Milk yield was increased by the addition of fat, being influenced by source and by dose. The milk fat was influenced by source of fat supplementation. The ruminal pH was not affected by experimental treatments. Supplementation with CSSO damaged the fiber degradation, reduced production of VFA \'s, reduced microbial synthesis and the production of milk fat compared with the source of CSPO. In conclusion, DM intake and digestibility were better predicted with the use of titanium dioxide as a marker. Furthermore, supplementation with calcium salts of palm oil increased milk production in lactating without decreasing DM intake and degradation of the fiber.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-03-26T15:01:12Z No. of bitstreams: 1 Jacqueline Lopes Nunes.pdf: 1696840 bytes, checksum: 410a2c3a174ef900d213e9b13078cac1 (MD5) / Made available in DSpace on 2015-03-26T15:01:12Z (GMT). No. of bitstreams: 1 Jacqueline Lopes Nunes.pdf: 1696840 bytes, checksum: 410a2c3a174ef900d213e9b13078cac1 (MD5) Previous issue date: 2012-05-23 / CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico / O acesso à energia elétrica é um dos principais fatores que resultam no desenvolvimento socioeconômico de uma nação. Essa, por sua vez, não tem sido ofertada de forma suficiente para atender as regiões Norte e Nordeste, o que dificulta, sobremaneira, o funcionamento das principais necessidades de um cidadão, como hospitais e escolas. Apesar disso, essas regiões são dotadas de condições climáticas ideais para a plantação de dendê, no caso da região Norte, e radiação solar, no caso da região Nordeste, que as potencializam para geração de energia elétrica. Assim, esta dissertação procura determinar a capacidade de geração de energia elétrica nestas regiões e o impacto que poderá decorrer, em termos de emprego e renda, nas mesmas. A metodologia utilizada na pesquisa foi documental, utilizando-se de pesquisa bibliográfica. Ao final deste trabalho concluiu-se que o dendê, na região Norte, e solar, no Nordeste, poderá propiciar benefícios fiscais e econômicos significativos, contribuindo numa proporção elevada na oferta de energia elétrica das regiões. Sendo que o dendê, além de gerar emprego e renda à população, poderá suprir as necessidades energéticas dos Sistemas Isolados. Em se tratando da energia solar, esta poderá propiciar não somente emprego e renda, mas também oportunidades de negócios já que é possível desenvolver outras atividades comerciais. Além disso, foi constatado que essa fonte de energia pode ser determinante para o abastecimento energético dos locais com baixa eletrificação, suprindo até mesmo a demanda desses locais para o ano de 2030. / The access to the electric power supply is an essential component for the economic and social development of a country. However its generation has not been enough in order to supply the North and Northeast regions of Brazil, which difficulty the operations of the main necessities of a citizen, like hospitals and schools. Nevertheless, these regions have ideal climatic conditions to palm oil plantation, in North region, and solar radiation, in Northeast region, to enhance the generation of electricity. This dissertation analyses the potential of the electric power supply in the North and Northeast of Brazil and also check the socioeconomics impacts derived from them. The methodology is documental, using bibliographic research. The dissertation concludes that the palm oil, in the North region, and solar, in Northeast, could provide fiscal and economic benefits, as well as to electric power supply for these regions. The palm oil could provide not only employment and income to population, but also could supply the demand of energy required by the Isolated Systems. Regarding the solar energy, it would provide not only employment and income, but also business opportunities to the region, since it provides possibilities to develop new commercial activities. Furthermore, this energy source could be determinant for the energy supply of places with low electrification and could supply this region in 2030.

Objetivou-se avaliar a inclusão de fontes de gordura na forma de sais de cálcio na dieta sobre o desempenho e metabolismo de vacas em início e meio da lactação mantidas em pastagens tropicais. No Capítulo 3, foi realizada uma meta-análise para avaliar os efeitos da suplementação de gordura para vacas mantidas em pastagens sobre a produção e a composição do leite. A produção de leite aumentou com a suplementação de gordura, e a suplementação com fontes insaturadas deprimiu o teor de gordura do leite. No capítulo 4, objetivou-se comparar o uso do dióxido de titânio (TiO2) como marcador externo em substituição ao óxido crômico (Cr2O3) para estimar a excreção fecal e calcular o consumo de forragem e a digestibilidade. A excreção fecal tendeu ser maior para os valores estimados pelo Cr2O3. O Cr2O3 superestimou a excreção fecal comparado com a coleta total de fezes. O consumo de forragem e o consumo de MS total foram superestimados pelo Cr2O3, enquanto não foram observadas diferenças entre os valores observados de consumo e estimados pelo TiO2. A digestibilidade aparente da MS foi subestimada tanto pelo Cr2O3 quanto pelo TiO2. No capítulo 5 objetivou-se avaliar os efeitos da suplementação de vacas em início da lactação mantidas em pastagem tropical com diferentes fontes de gordura sobre o desempenho, composição do leite e variáveis produtivas ao longo da lactação. A suplementação de sais de cálcio de óleo de soja (SCOS) aumentou a produção de leite quando comparado com o grupo controle, porém foi inferior a produção dos animais suplementados com sais de cálcio de óleo de palma (SCOP). Apesar do aumento em produção de leite com SCOS, nesse tratamento o teor de gordura do leite reduziu significativamente quando comparado com o grupo controle e ao SCOP. Durante o período residual a produção do grupo que recebeu SCOP continuou maior e refletiu na produção ao longo de toda a lactação (7328 kg lactação-1) comparado ao SCOS (6575 kg lactação-1) e ao controle (6094 kg lactação-1). No capítulo 6, objetivou-se avaliar a suplementação de duas fontes e duas doses de sais de cálcio de ácidos graxos sobre o desempenho, composição do leite, parâmetros ruminais e metabólicos e balanço energético de vacas no meio da lactação mantidas em pastagem tropical. A produção de leite foi afetada pela adição de gordura, sendo influenciada pela fonte e pela dose de gordura. O teor de gordura do leite foi influenciado pela fonte de gordura suplementada. O pH ruminal não foi afetado pelos tratamentos experimentais. A suplementação com SCOS prejudicou a degradação da fibra, reduziu a produção de AGV\'s, reduziu a síntese microbiana e a produção de gordura do leite quando comparado com a fonte de SCOP. Portanto, as estimativas de consumo e digestibilidade foram melhores preditas com o uso do dióxido de titânio como marcador. Além disso, a suplementação com sais de cálcio de óleo de palma aumentou a produção de leite na lactação, não reduziu o consumo e nem a degradação da fibra. / The objective of this study was to evaluate inclusion of different sources of fat as calcium salts in the diet on performance and metabolism of early lactation cows grazing tropical pastures. In Chapter 3, a meta-analysis was performed to evaluate the effects of fat supplementation to grazing dairy cows on milk yield and milk composition. Milk yield increased with fat supplementation, and supplementation with unsaturated sources depressed milk fat content. In Chapter 4, the objective was to compare the use of titanium dioxide (TiO2) as an external marker to replace chromium oxide (Cr2O3) to estimate fecal excretion and calculate forage intake and digestibility. Fecal excretion tended to be greater for values estimated by Cr2O3. The Cr2O3 overestimated and TiO2 tended to overestimate fecal excretion compared to total fecal collection. Forage intake and total DM intake were overestimated by Cr2O3, while no differences were observed between the observed values of consumption and estimated by TiO2. The apparent DM digestibility was underestimated by both Cr2O3 and TiO2. In the chapter 5, it was evaluated the effects of fed different sources of fat to early lactation cows (from 15 to 105 DIM) grazing a tropical pasture on production variables throughout lactation (until 280 DIM). Calcium salts of soybean oil (CSSO) increased milk yield compared to control, but was lower than the production of animals supplemented with calcium salts of palm oil (CSPO). Despite the increase in milk yield with CSSO, this treatment decreased milk fat content and yield when compared with control and CSPO. During the residual period (from 106 to 280 DIM) the group that received CSPO had greater milk yield and reflected in the greater milk yield throughout lactation (7328 kg lactation-1) compared to CSSO (6575 kg lactation-1) and the control (6094 kg lactation-1). In chapter 6, the objective was to evaluate the supplementation with two sources (CSSO vs. CSPO) and two doses (400g vs 700g/day) of calcium salts of fatty to mid lactating dairy cows grazing a tropical pasture on performance, milk composition, ruminal and metabolic parameters and energy balance. Milk yield was increased by the addition of fat, being influenced by source and by dose. The milk fat was influenced by source of fat supplementation. The ruminal pH was not affected by experimental treatments. Supplementation with CSSO damaged the fiber degradation, reduced production of VFA \'s, reduced microbial synthesis and the production of milk fat compared with the source of CSPO. In conclusion, DM intake and digestibility were better predicted with the use of titanium dioxide as a marker. Furthermore, supplementation with calcium salts of palm oil increased milk production in lactating without decreasing DM intake and degradation of the fiber.